Mounting for driving units on motorboats



May 6, 1952 A. e. LOOFBOURROW 2,595,363

MOUNTING FOR DRIVING UNITS 0N MOTORBOATS Filed July 7, 1949 2SHEETS-SHEET 1 IN VEN TOR.

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A. G. LOOFBOURROW MOUNTING FOR DRIVING UNITS ON MOTORBOATS Filed July 7,1949 INVENTOR. /y/477 C2 Zoo/Zazzrvv a/wwfl W Patented May 6, 1952MOUNTING FOR DRIVING UNITS ON MOTORBOATS Alan G. Loofbourrow,Birmingham, Mich., as-

signor to Chrysler Corporation, Highland Park, Mich, a corporation ofDelaware Application July 7, 1949, Serial No. 103,412

6 Claims.

This invention relates to an improved mounting for the driving unit orpower train of a motor boat and more particularly to mounting meansoperable to accommodate limited universal movement of the propellerrelative to the hull of a motor boat.

In conventional motor boat construction a propeller shaft which operablyconnects an engine with a propeller is mounted so that it is inclinedrelative to the surface of the water or direction 1 of travel of theboat. In constructions of this type it is evident that the plane ofrotation of the propeller is inclined to the vertical plane which wouldbe normal to the direction of travel of the boat. The propeller isdesigned to operate as a screw movingon an axis corresponding to itspropeller shaft while actually it is dragged through the water at anangle to its axis. This produces a dynamic unbalance which impartslateral forces to the propeller which tend to move it and producevibration. Heretofore, in the construction of motor boats the propellershaft has been secured to the hull so that lateral movements thereofinduced by the dynamic unbalance were transmitted to the hullandproduced vibration therein.

It is a principal object of this invention to so mount the propeller andits shaft relative to' the hull of a boat that a limited amount ofrelatively unrestrained universal motion of the propeller relative tothe hull is accommodated. This permits the propeller and. its shaft tomove in response to forces imparted thereto by its dynamic unbalancewithout vibrating the hull.-

In order to accommodate a limited. universal movement of the propellerrelative to the hull it becomes necessary to incorporate in the drivingunit of the boat means to accommodate such.

universal movement and to provide means to transmit thrust from thepropeller to the hull which is capable of accommodating such limiteduniversal movement. It is an object of this invention to provide anovel. driving unit that possesses these necessary attributes.

In the drawings:

Fig. 1 is a diagrammatic view inside elevation and partly in sectionshowing a motor boat incorporating my invention;

Fig. 2 is a fragmentary view partly in section of a stuffing box;

Fig. 3 is a view taken on the line 3-3 of Fig. 1 showing a strut whichsupports the propeller shaft on the hull;

Fig. 4 is a diagrammatic view of the driving unit showing the propellershaft in several of its possible positions;

Fig. 5 is a fragmentary view partly in section of a portion of thedriving unit;

Fig. 6 is a section taken substantially on the line 6--6 of Fig. 5 withthe supporting brackets included in the view as indicated by the line6-6 of Fig. 7;

Fig. 7 is a top plan view of the device illustrated in Fig. 6;

Fig. 8 is a section on the line 88 of Fig. 5; and

Fig. 9 is a fragmentary enlargement of the bearing and associated partsshown in Fig. 5.

In Fig. 1 a motor boat Ii! is illustrated as including an engine [2supported on the hull by engine mountings I4, a transmission It and apropeller shaft i8 carrying a propeller 28. A

' thrust transmitting device 22 connects the propeller shaft IS with thehull of the boat and a universal joint means 24 is interposed betweenthe device 22 and a shaft 94 extending from the transmission IS. A strutor propeller shaft supporting bracket 26 which depends from the exteriorof the hull has a portion while circumscribes the shaft [8 and includesa relatively flexible material operable to accommodate rocking movementof the shaft l8 relative thereto. The bracket 26 serves as a fulcrumabout which the propeller shaft l8 rocks in response to lateral forcesapplied to the propeller by reason of its dynamic unbalance and theuniversal joint means 24 serves to drivingly connect the movable shaft[8 with the engine and its associated transmission. A stuffing box 28serves to prevent the admission of water to the hull at the point wherethe hull is penetrated by the propeller shaft [8.

The stufiing. box 28 is illustrated in more detail in Fig. 2 andcomprises a bearing 30 which circumscribes the propeller shaft 18 and acasting 32 which is secured to the hull around an opening therein. Arubber tube 3 1 surrounds the shaft l 8 and is fastened by a hose clamp36 to the bearing 30. A second hose clamp 38 serves to secure the otherend of the rubber tube to a collar 40" which is carried by the casting32 so that a fluid seal is effected and the admission of water to theinterior of the boat is thus prevented although the shaft [8 ispermitted to rotate in the bearing 39 and to have universal movement relative to the casting 32.

In. Fig. 3' the propeller shaft supporting bracket 26 is illustrated assecured to the underside of the hull of the boat Hi. The bracket 26 isprovided with an annular portion 44 which is penetrated by the shaft 13and a relatively hard rubber bearing. 46 of conventional marineconstruction circumscribes the shaft [8 and is carried by the bracket 26by means of a relatively soft rubber ring 48- which' permits limitedrocking movement of the shaft i8 and bearing 46 relative to the bracket26.

The thrust transmitting device 22 includes an arm or strut 59 whichextends laterally of the boat and which is mounted in a manner to bedescribed on brackets 52 carried by the hull of the boat. Any suitablemeans for connecting the arm or strut 50 to the propeller shaft I8 sothat the shaft can rotate relative to the arm and yet transmit thrust tothe arm would be satisfactory although the particular thrusttransmitting connection illustrated will be described. In Fig. a collar54 is illustrated as circumscribing the input end of the shaft I8 andbeing secured thereto by a plurality of bolts 56. A second collar 58 iscarried by the first collar and secured thereto by bolts 60 and thecollar 58 abuts an annular bearing element 62 which in turn abuts a hubor collar 64. The collar 58, bearing element 62 and hub 64 are boltedtogether by a splined stub shaft 66 and a pair of nuts 68 so that thesepart operate as an integral unit. The bearing element 62 and a secondannular bearing element 19 carry aligned raceways in which a pluralityof balls I2 are carried. A pair of complementary annular rings 14 and I6are disposed on opposite sides of arm and abut the sides of annularbearing I0 to retain the latter in position. Hub 64, bearing element 62and collars 58 and 54 rotate as a unit with shaft I8 and the balls I2accommodate this rotation relative to the annular bearing element I0,arm 50 and annular rings I4 and I6. Longitudinal thrust from the shaftI8 is transmitted through collars 54 and 58 to bearing element 62 andthrough bearing element 62 to ball I2 which reacts against the racewayin annular bearing element I0 to impart thrust to annular ring I4 andarm 50, as illustrated in Fig. 9, so that the arm 50 moves forward as anincident to rotation of the propeller in the water.

The arm 50 which is carried in the manner described by the propellershaft I8 is suspended from a plurality of bolts 80 carried by thebrackets 52 which are secured to the hull of the boat. Each bolt 80carries a pair of flexible cushion elements 82 and 84 which arepreferably fabricated of rubber and which circumscribe the bolt 80 onopposite sides of the arm 50 as illustrated in Fig. 7. Each bolt 80 alsocarries a washer 86 which abuts the exposed end of the associatedcushion element 82. The thrust transmitted to the arm 50 from thepropeller, as above described, is in turn transmitted to the hull of theboat by compression of the flexible elements 84 against the brackets 52.If desired, the flexible elements 82 and 84, may be bonded to the arm 50and washers 86. It will thus be seen that the shaft I8 is supported inthe arm 50 for rotation relative thereto, but that radial movement ofthe shaft I8 and am 50 relative to the hull may be accommodated bydistortion of the elements 82 and 84 so that vibration inherent in theshaft I 8 due to the dynamic unbalance of the propeller will not betransmitted directly to the hull.

In view of the fact that the forces of dynamic unbalance are applied onthe outboard end of shaft I8 the shaft I8 and its associated partsfulcrum about strut or bracket 26 and a lateral movement or radialdisplacement of the hub 64 relative to shaft 94 is thereby produced. Inorder to accommodate this lateral movement of the hub 64 and provide adriving connection between this collar and. the engine and itsassociated parts which are fixed relative to the hull a pair ofconventional universal joints generally designated by the numerals 90and 92 are interposed between hub 64 and the shaft 94 which constitutesthe driven shaft of the transmission I6. The shaft 94 has a hub I00drivingly mounted thereon and this hub has a flange I02 extendingradially from its inner end and carrying a housing I04. As

best shown by Fig. 8, the housing I04 is shaped to provide diametricallyopposed guideways I06 and I08 and in intermediate passage IIO which issubstantially larger than the guideways. The flange I02 has cavities orrecesses II2 which in effect elongate the guideways. At the opposite endof the body I04, a circular plate H4 is fastened to the body. The plateI I4 extends radially inwardly and carries a cylindrical sleeve II6which extends axially of the shafts I8 and 94. It will be observed thatthe plate I I4 acts as an end wall which extends over the ends ofguideways I06 and I08.

An identical structure is fastened to the collar 64 with correspondingnumerals identifying like parts. Thus, two sleeves II6--I I6 extendtowards each other although it still be observed that they are spacedaxially a substantial distance. For sealing the space between the endsof these sleeves, a sealing band, which may comprise rubber as indicatedat II8, extends around the ends of the sleeves and in order to preventloosening of the band, adjustable clamps I20 positively hold the ends ofthe band. It should be evident that this band permits either shaft withits housing and other parts connected thereto to move radially or atangle with respect to the othershaft and the parts connected to it.

A central connecting shaft 96 extends longitudinally in the sleeves I I8and opposite ends of this shaft project into the central passages I Inin the housings I04. Each end of this shaft has a diametricallyextending pin I22 securely held in position and opposite ends of the pinare provided with ball elements and centering buttons indicated at I24and I26 respectively.

Springs I28 are adapted to resiliently position the connecting shaft 96axially of the joint assembly so as to prevent shifting of the memberaxially at least in an undesirable manner. In other words, the springstend to centralize the connecting shaft 96 axially of the assembly whilestill permitting axial movement of the connecting shaft and other parts.

It will be apparent that the shafts I8 and 94 can be pulled apart oraway from each other and that movement of ball elements I24 in guidewaysI96 and I08 and the band II8 will allow such movement. It is likewiseapparent that the shafts can be moved towards each other if necessaryagainst the action of the springs. Furthermore, it will be apparent thatthe shafts l8 and 94 can operate at an angle to each other and that theparts will take relative positions in accordance with the movementsrequired. When the shafts I8 and 94 are at an angle to each other andthe adjacent ends thereof are laterally displaced the collar 64 will becarried by shaft I8 and hub I00 will be carried by shaft 94. The ballelements I24 will move longitudinally and tilt in guideways I06 and I08to accommodate the necessary tilting of connecting shaft 96 and thechange in the distance between collar 64 and hub I00 will beaccommodated by band H8 and movement of the ball elements longitudinallyin the guideways.

Fig. 4 diagrammatically illustrates the positions assumed by the partsas an incident to movement of the propeller under the influence of thelateral forces imparted thereto by its dynamic unbalance. The motor I2,transmission I6 and shaft 94 are secured to the hull while the propellershaft I8 carrying the propeller 20 is fulcrummedabout the str-ut orbracket 26. The universal joint means and 92 permits stub shaft 96 toassume positions similar to those illustrated on an exa gerated scale inFig. 4 to accommodate a driving connection between the shafts 94 and 18-in spite of the lateral or radial movement of the inboard end of theshaft l8 and the thrust transmitting device 22 transmits longitudinalthrust to the hull of the boat from shaft l8 While the cushion ele ments82 and 84 incorporated in the device 22 accommodate the movement of theshaft I 8 rela tive tothe hull.

I claim:

1. In a motor boat, a hull, a propeller shaft extending through saidhull and having a, propeller secured thereto on its outboard end, apropeller shaft supporting bracket depending from the exterior of saidhull and having a bearing circumscribing said propeller shaft andmounted in said bracket for limited rocking movement relative to saidbracket to accommodate rocking movement of said propeller shaft in saidbracket with said bracket as the fulcrum, an engine mounted in said hulland having a driving shaft terminating in close proximity to the inboardend of said propeller shaft, a double universal joint means driving- 1yconnecting said driving shaft and the inboard end of said propellershaft, said universal joint means including means to accommodate limitedradial displacement between adjacent ends of said driving shaft and saidpropeller shaft effected by rocking movement of said propeller shaftabout said bracket as a fulcrum, a strut extending transversely of saidpropeller shaft intermediate said bracket and said universal joint meansand having a bearing circumscribing said propeller shaft and operable toaccommodate rotation of said propeller shaft relative to said strut,cooperating means carried by said bearing and said propeller shaftoperable to transmit thrust longitudinally of said propeller shaft tosaid strut, and a resilient supporting structure mounting said strut onsaid hull and operable to transmit said longitudinal thrust to said hulland accomodate limited radial movement of said propeller shaft and strutrelative to said hull.

2. In a motor boat, a hull, a propeller shaft extending through saidhull and having a propeller secured thereto on its outboard end, apropeller shaft supporting bracket depending from the exterior of saidhull, said bracket including an annular portion, a bearingcircumscribing said propeller shaft and located in said annular portionand a rubber ring circumscribing said bearing and mounted within saidannular portion to accommodate limited rocking movement of said bear ingrelative to said bracket as an incident to rocking movement of saidpropeller shaft in said bracket with said bracket as the fulcrum, anengine mounted in said hull and having a driving shaft terminating inclose proximity to the inboard end of said propeller shaft, a doubleuniversal joint means drivingly connecting said driving shaft and theinboard end of said propeller shaft, said universal joint meansincluding means to accommodate limited radial displacement betweenadjacent ends of said driving shaft and said propeller shaft eifected byrocking movement of said propeller shaft about said bracket as afulcrum, a strut extending transversely of said propeller shaftintermediate said bracket and said universal joint means and having abearing circumscribing said propeller shaft and operable to accommodaterotation of said propeller shaft relative to said strut, cooperatingmeans carried by said bearing and said propeller shaft operable totransmit thrust longitudinally of said propeller shaft to said strut,and a resilient supporting structure mounting said strut on said hulland operable to transmit said longitudinal thrust to said hull andaccommodate limited radial movement of said propeller shaft and strutrelative to said hull.

3. In a motor boat, a hull, a propeller shaft extending through saidhull and having a propeller secured thereto on its outboard end, apropeller shaft supporting bracket depending from the exterior of saidhull and having a bearing circumscribing said propeller shaft andmounted in said bracket for limited rocking movement relative to saidbracket to accommodate rocking movement of said propeller shaft in saidbracket with said bracket as the fulcrum, an engine mounted in said hulland having a driving shaft terminating in close proximity to the inboardend of said propeller shaft, a double universal joint device drivinglyconnecting said driving shaft and the inboard end of said propellershaft, said universal joint device including a hub drivingly carried bysaid driving shaft, a hub drivingly carried by said propeller shaft,each of said hubs being provided with diametrically opposed guidewaysextending longitudinally of their associated shaft, a, connecting shaftlocated intermediate said hubs and having a diametrically extending pinsecured to each end portion thereof, each of said pins having a ballelement carried by each end thereof, one of said ball elements beingpositioned in each of said guideways to mount said connecting shaft foruniversal movement relative to said driving shaft and relative to saiddriven shaft, said ball elements being adapted to move longitudinally ofsaid guideways to accommodate limited longitudinal extension andcontraction of said device which occurs as an incident to relativeradial displacement of the adjacent ends of said driving and drivenshafts effected by rocking movement of said propeller shaft about saidbracket as a fulcrum, a strut extending transversely of said propellershaft intermediate said bracket and said universal joint device andhaving a bearing circumscribing said propeller shaft and operable toaccommodate rotation of said propeller shaft relative to said strut,cooperating means carried by said bearing and said propeller shaftoperable to transmit thrust longitudinally of said propeller. shaft tosaid strut, and a resilient supporting structure mounting said strut onsaid hull and operable to transmit said longitudinal thrust to said hulland accommodate limited radial movement of said propeller shaft andstrut relative to said hull.

l. In a motor boat, a hull, a propeller shaft extending through saidhull and having a propeller secured thereto on its outboard end, apropeller shaft supporting bracket depending from the exterior of saidhull and having a bearing circumscribing said propeller shaft andmounted in said bracket for limited rocking movement relative to saidbracket to accommodate rocking movement of said propeller shaft in saidbracket with said bracket as the fulcrum, an engine mounted in said hulland having a driving shaft terminating in close proximity to the inboardend of said propeller shaft, a double universal joint means drivinglyconnecting said driving shaft and the inboard end of said propellershaft, said universal joint means includ- 'ing means to accommodatelimited radial displacement between adjacent ends of said driving shaftand said propeller shaft effected by rocking movement of said propellershaft about said bracket as a fulcrum, a strut extending transversely ofsaid propeller shaft intermediate said bracket and said universal jointmeans, a second bearing in which said propeller shaft is journalled,said second bearing being carried by said strut and adapted toaccommodate rotation of said propeller shaft relative to said strut,cooperating means carried by said bearing and said propeller shaftoperable to transmit thrust longitudinally of said propeller shaft tosaid strut, and a supporting structure mounting said strut on said hulland operable to transmit said longitudinal thrust to said hull andaccommodate limited radial movement of said propeller shaft and strutrelative to said hull, said supporting structure including a boltextending through said strut and having a first end thereof secured tosaid hull and a pair of rubber cushion elements interposed respectivelybetween said first end of said bolt and one side of said strut andbetween the other end of said bolt and the other side of said strut.

5. In a motor boat, a hull, an engine supported in said hull and havinga driving shaft, a propeller shaft extending through said hull andhaving a propeller secured thereto on its outboard end, a propellershaft supporting bracket mounted on the exterior of said hull, a bearingcircumscribing the outboard portion of said propeller shaft and carriedby said bracket for limited rocking movement relative thereto, a bearingmounted on said hull for the transmission of longitudinal thrust theretoand for limited movement transverse of the propeller shaft and operableto transmit thrust longitudinally of said propeller shaft to said hull,said propeller shaft being journalled in said bearing, cooperating meanscarried by said propeller shaft and said bearing to transmit thrustlongitudinally of said propeller shaft to said bearing, and meansforming a drive transmitting connection between said driving shaft andsaid propeller shaft and operable to accommodate relative lateralmovement between the inboard end of said propeller shaft and saiddriving shaft to accommodate rocking of said propeller shaft about saidbracket as a fulcrum.

6. In a motor boat, a hull, a propeller shaft extending through saidhull and having a propeller secured thereto on its outboard end, a

propeller shaft supporting bracket depending from the exterior of saidhull and having a bearing circumscribing said propeller shaft andmounted in said bracket for limited rocking movement relative to saidbracket to accommodate rocking movement of said propeller shaft in saidbracket with said bracket as the fulcrum, an engine mounted in said hulland having a driving shaft terminating in close proximity to the inboardend of said propeller shaft, a double universal joint means drivinglyconnecting said driving shaft and the inboard end of said propellershaft, said universal joint means including means to accommodate limitedradial displacement between adjacent ends of said driving shaft and saidpropeller shaft effected by rocking movement of said propeller shaftabout said bracket as a fulcrum, an arm carried by said propeller shaftintermediate said bracket and said universal joint means, cooperatingmeans carried by said shaft and said arm to establish a connectiontherebetween for the transmission of thrust longitudinally of saidpropeller shaft, and a resilient supporting structure mounting saidstrut on said hull and operable to transmit said longitudinal thrust tosaid hull and accommodate limited radial movement of said propellershaft and strut relative to said hull.

ALAN G. LOOFBOURROW.

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UNITED STATES PATENTS Number Name Date 821,925 Collier May 29, 1906830,908 Martin Sept, 11, 1906 833,364 Arthur Oct. 16, 1906 1,555,214Johnson Sept. 29, 1925 2,002,517 Balduf May 28,- 1935 2,046,558 HussmanJuly 7, 1936 2,103,087 Morris Dec. 21, 1937 2,265,079 Mettair Dec. 2,1941 2,306,664 Scott-Paine Dec. 29, 1942 2,338,796 Berquist Jan. 11,1944 2,360,786 Miguelon Oct. 17, 1944 2,465,785 Berno Mar. 29, 1949

